Packet transmission method, packet transmission system and packet data transmission medium on mobile communications network system

ABSTRACT

An address structure in mobile communications network facilitating routing of a packet. At the initial position of the address, is located a prefix or the like indicating the type of the address structure, which indicates the present mobile communications network system, for example. At the next position, a location address (LA) is located characterizing the present invention. The location address is usually placed at the position of a subnetwork address. The location address (LA) is provided for each mobile switching system, and constitutes part of an IP address of a user using a mobile station under the control of the mobile switching system. At the final position, is located a user identifier (user ID) which is used for identifying a user, and is provided uniquely for each user. The IP address in accordance with the present invention can be split into the foregoing three sections, part of which includes the location address and user identifier indicating the location of the mobile station in the mobile communications network, thereby enabling the identification of the user in the mobile communications network system and the control of the packet transmission.

TECHNICAL FIELD

The present invention relates to a packet transmission method, a packettransmission system and a packet data transmission medium fortransmitting digital information on a mobile communications networksystem, and more particularly to a packet transmission method, a packettransmission system and a packet data transmission medium according tothe IP, the Internet protocol.

BACKGROUND ART

Conventionally, there has been a packet transmission system such as theInternet constructed on a mobile communications network system. Theconventional system carries out unique control inherent in the mobilenetwork to achieve location address management and pursuit callinginherent in mobile radio communications. To perform the unique controlinherent in the mobile radio communications on the packet informationsent from other systems, IP datagram encapsulation according to theknown communications RFC technique is carried out (see, pp. 800–803 of“Internet RFC handbook” supervised by Hidematsu KASANO, Ascii Corp.Tokyo, 1998). It converts in a fixed node of the mobile communicationsnetwork system the packet information into a packet according to theprotocol of the mobile communications network system by encapsulatingthe packet information with a packet according to the protocol in themobile communications network system, and transmits the packet throughthe mobile communications network system. The packet is transmitted to amobile station after removing the encapsulating packet in a fixed nodenear the mobile station in the mobile communications network system.

Such a conversion, however, imposes overload on the node that carriesout the conversion according to the protocol of the mobilecommunications network system.

Besides, the encapsulation of the packet increases an amount of theinformation to be transmitted by that amount.

In addition, the transmission path can be lengthened because theinformation is transmitted to the mobile station through the fixed nodethat carries out the protocol conversion service.

However, constructing a seamless system matching an external protocol isdifficult because the transmission path of the packet cannot beidentified as in the fixed network because of the roaming of a terminalin the mobile communications network system.

An object of the present invention is to construct on the mobilecommunications network system a seamless packet transmission system thatcan obviate the necessity for carrying out the protocol conversionbetween the mobile communications network system and an external packettransmission system.

DISCLOSURE OF THE INVENTION

To accomplish the object, the present invention provides a packettransmission method in a mobile communications network system forrouting a packet using an IP address between a user in a mobilecommunications network system and a user inside or outside the mobilecommunications network system, the packet transmission method comprisingthe steps of:

-   -   storing a location address and a user identifier of the user in        the mobile communications network system into the IP address        within a packet transmitted and/or received by the user in the        mobile communications network system; and    -   routing the packet in accordance with the location address and        the user identifier in the IP address. This makes it possible to        implement a packet transmission method based on the IP address        throughout the mobile communications network system and the        external system.

The location address may have a hierarchical structure.

The hierarchical structure may comprise at least a network identifierindicating a subdivided network of the mobile communications network,and a node identifier provided in connection with a termination node ofan access link in the network.

The packet transmission method further comprising the steps of:

-   -   routing the packet to the network in accordance with the network        identifier;    -   routing the packet to the termination node in accordance with        the node identifier; and    -   transmitting the packet from the termination node by selecting        an access link of a related mobile communications network in        accordance with the user identifier.

The packet transmission method further comprising the steps of:

-   -   routing the packet to the termination node, referring to the        location address in its entirety; and    -   transmitting the packet from the termination node by selecting        an access link of a related mobile communications network in        accordance with the user identifier.

At least the location address constituting the IP address may betransmitted to the user in the mobile communications network system orto the user inside or outside the mobile communications network system,when an access link is established between the user in the mobilecommunications network system and the mobile communications networksystem.

The packet transmission method further comprising the steps of:

-   -   storing an IP address in connection with a domain name in a        database in a domain-name server;    -   having the domain-name server send the IP address back to the        user in the mobile communications network system or to the user        inside or outside mobile communications network system in        response to an inquiry from the user about the IP address using        the domain name; and    -   having the user that sends the inquiry carry out a packet        communication using the IP address sent back.

The inquiry is sent to the domain-name server, if the access link is notestablished then an access link is established.

The domain-name server generates the IP address by acquiring from themobile communications network system a location address of the user inthe mobile communications network system. Thus managing the IP addressby the domain-name server enables the packet communications by the IPaddress including a location address.

The packet including the IP address may be routed in accordance with theIP address with or without encapsulating the packet.

The foregoing object of the present invention can also be implemented inthe form of the following packet transmission system. Specifically, thepresent invention provides a packet transmission system in a mobilecommunications network system for routing a packet using an IP addressbetween a user in a mobile communications network system and a userinside or outside the mobile communications network system, the packettransmission system comprising:

-   -   means for storing a location address and a user identifier of        the user in the mobile communications network system into the IP        address within a packet transmitted and/or received by the user        in the mobile communications network system; and    -   means for routing the packet in accordance with the location        address and the user identifier in the IP address. This makes it        possible to implement a packet transmission system based on the        IP address throughout the mobile communications network system        and the external system.

The location address may have a hierarchical structure. The hierarchicalstructure may comprise at least a network identifier indicating asubdivided network of the mobile communications network, and a nodeidentifier provided in connection with a termination node of an accesslink in the network.

The packet transmission system further comprising:

-   -   means for routing the packet to the network in accordance with        the network identifier;    -   means for routing the packet to the termination node in        accordance with the node identifier; and    -   means for transmitting the packet from the termination node by        selecting an access link of a related mobile communications        network in accordance with the user identifier.

The packet transmission system further comprising:

-   -   means for routing the packet to the termination node, referring        to the location address in its entirety; and    -   means for transmitting the packet from the termination node by        selecting an access link of a related mobile communications        network in accordance with the user identifier.

At least the location address constituting the IP address may betransmitted to the user in the mobile communications network system orto the user inside or outside the mobile communications network system,when an access link may be established between the user in the mobilecommunications network system and the mobile communications networksystem.

The packet transmission system further comprising:

-   -   a domain-name server including a database storing an IP address        in connection with a domain name;    -   means for having the domain-name server send the IP address back        to the user in the mobile communications network system or to        the user inside or outside mobile communications network system        in response to an inquiry from the user about the IP address        using the domain name; and    -   means for having the user that sends the inquiry carry out a        packet communication using the IP address sent back.

The inquiry may be sent to the domain-name server, if the access link isnot established then an access link is established.

The domain-name server may generate the IP address by acquiring from themobile communications network system a location address of the user inthe mobile communications network system. Thus managing the IP addressby the domain-name server enables packet communications by the IPaddress including a location address.

Furthermore, the present invention provides the packet transmissionsystem further comprising a domain-name server including a database forstoring an access link termination node in a subdivided network in themobile communications network in connection with an IP address and adomain name; wherein the access link termination node includes:

-   -   access link management means for establishing or releasing an        access link;    -   means for storing the location address;    -   means for storing user location registration information in a        memory in response to a location registration request from a        user, and for providing the user with the location address of        the user; and    -   means for transmitting the user location registration        information to the domain-name server in response to the        location registration request from the user, and    -   wherein the domain-name server includes:

-   means for storing the IP address including the location address of    the user;    -   means for receiving the user location registration information        from the access link termination node; and    -   means for updating the IP address using the user location        registration information received.

The packet including the IP address may be routed in accordance with theIP address with or without encapsulating the packet.

Finally, the foregoing object of the present invention can beimplemented in the form of the following packet data transmissionmedium. Specifically, a packet data transmission medium in a mobilecommunications network system for routing a packet using an IP addressbetween a user in a mobile communications network system and a userinside or outside the mobile communications network system, the packetdata transmission medium storing a location address and a useridentifier of the user in the mobile communications network system intothe IP address within a packet transmitted and/or received by the userin the mobile communications network system.

The location address may have a hierarchical structure.

The hierarchical structure may comprise at least a network identifierindicating a subdivided network of the mobile communications network,and a node identifier provided in connection with a termination node ofan access link in the network.

The packet data transmission medium may consist of a packet data signal.

The configuration according to the present invention can facilitate thepacket transmission in the mobile communications network and from theoutside. This is because it incorporates the location address (LA) anduser identifier as an integral part of the IP address.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a mobile communications network systemfor constructing a packet transmission system in accordance with thepresent invention;

FIG. 2 is a diagram illustrating a structure of an IP address includinga location address (LA) used in the present invention;

FIG. 3 is a diagram illustrating IP address acquisition when originatinga packet communication from a mobile communications network inaccordance with the present invention;

FIG. 4 is a diagram illustrating IP address acquisition when originatinga packet communication from another user in accordance with the presentinvention;

FIG. 5 is a diagram illustrating an access link setting carried out whena power supply is turned on in accordance with the present invention;

FIG. 6 is a diagram illustrating an access link setting carried out whenaccessing a domain-name server in accordance with the present invention;

FIG. 7 is a diagram illustrating registration to a domain-name server ofthe correspondence between a mobile station identity IMUI and name inaccordance with the present invention;

FIG. 8 is a diagram illustrating an access link setting carried outusing the IMUI in accordance with the present invention;

FIG. 9A and FIG. 9B are diagrams illustrating a hierarchical locationaddress in accordance with the present invention;

FIG. 10 is a diagram showing the relationship between FIGS. 10A and 10B;

FIGS. 10A and 10B are diagrams illustrating routing carried out using alocation address in accordance with the present invention;

FIG. 11 is a block diagram showing a hardware configuration of an M-DNSin accordance with present invention; and

FIG. 12 is a block diagram showing a hardware configuration of an IP-CNVin accordance with the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The preferred embodiments in accordance with the invention will now bedescribed with reference to the accompanying drawings. The followingpreferred embodiments in accordance with the present invention are onlyexamples of the present invention. The present invention is not limitedby the embodiments, and can be implemented by other embodiments.

FIG. 1 schematically shows a mobile communications network system forimplementing the packet transmission in accordance with the presentinvention. First, a configuration of the mobile communications networksystem will be described.

A signal from a mobile station (MS) 102 (to which a user PC terminal orthe like not shown in this figure can be connected) is received by basestations (BS) 104 and 106, passes through a radio network center (RNC)108 or 110, and through a switching system such as a subscriber accessserver 112 or 114 and a routing node 116 or 118, and is connected to auser's telephone or PC terminal or the like (not shown) of an externalpublic circuit network 126 (such as INS-C, DDX-C and the like) or of apublic packet data network 128 (such as INS-P, DDX-P and the like). Amobile service control point (M-SCP) 124 functioning as a home memoryfor carrying out location management of mobile stations, whichcharacterizes the mobile communications network system, is accessedthrough a common channel signaling network 120.

On such a mobile communications network system, is constructed a packettransmission system (IP network: IP-NW) 150 using the IP of the Internetaccording to the present invention. To implement it, it is necessary forthe routing node or subscriber access server in the core network, a wireportion of the existing mobile communications network, to have a routerfunction for routing in accordance with IP addresses. The routerfunction is identical to the router function used on the Internet, whichcan be easily implemented by those skilled in the art. In the presentinvention, an IP converter (IP-CNV) characterizing the present inventionis installed in the subscriber access servers 112 and 114, and a mobiledomain-name server (M-DNS) 402 with special functions is installed as adomain-name server needed for the packet transmission of the Internet.These functions will be described below.

In FIG. 1, the subscriber access servers 112 and 114 include the IP-CNVoperating as a link termination node, and the IP-NW 150 includes them.However, a node for installing the IP-CNV in the mobile communicationsnetwork system may be the radio network centers (RNC) 108 and 110, basestations (BS) 106 and 104, or mobile station (MS) 102 in FIG. 1. Thus,the node installing the IP-CNV becomes a link termination node, and theIP-NW is composed of the node installing the IP-CNV and its higher ordernodes.

In the present embodiment, the IP-CNV is installed in the subscriberaccess server for convenience sake. Describing the embodiment will makeit obvious for those skilled in the art to apply the present inventionto cases in which the IP-CNV is installed in other nodes of anothermobile communications network system.

[Structure of an IP Address]

First, a structure of the IP address applied to the IP according to thepresent invention will be described with reference to FIG. 2. In FIG. 2,a prefix 202 is provided for indicating an address type such as a singleaddress, multicast address or the like. Next, a location address (LA)204, which characterizes the present invention, is provided. Thelocation address usually corresponds to a subnetwork address. Thelocation address is provided for each IP-CNV (such as a subscriberswitching system like a subscriber access server) operating as aterminal node of the access link in the network, and constitutes the IPaddress of a user communicating through the Internet using a mobilestation (102 of FIG. 1) under the control of the mobile switching system(112 of FIG. 1, for example). Finally, a user identifier (user ID) 206such as a mobile station identity IMUI is provided for identifying auser. It is uniquely assigned to each user.

The IP address according to the present invention can be split into theforegoing three components, part of which includes the user identifierand the location address indicating the location of the mobile stationin the mobile communications network. They are used in their entiretyfor identifying the user in the mobile communications network system,and for controlling the packet transmission.

Next, the hardware configuration of the M-DNS and IP-CNV characterizingthe present invention will be described with reference to FIGS. 11 and12.

[Hardware Configuration of the M-DNS]

A hardware configuration of an M-DNS is shown in FIG. 11. An M-DNS 1102comprises a CPU 1104, a user information database 1106 and externalinterface equipment 1108. The user information database 1106 storesdomain names and IP addresses (each of which includes a location addressand a user identifier) in the user information, and relates them to eachother. Other user information such as a telephone number or a linkidentifier like IMUI can also be stored and related to each other. Theexternal interface equipment 1108 functions as an interface forconnecting the M-DNS 1102 to an IP network 1110 or a common channelsignaling network 1112, which can be implemented by a common router, DSUor TA well-known as Internet technology. The CPU 1104 controls the userinformation database 1106 and external interface equipment 1108.Specifically, as will be described later in connection with anotherembodiment, the CPU 1104 receives user location registration information(such as the IP address including the location address and useridentifier) from the IP-CNV through the external interface equipment1108, and updates the IP address of the user information database 1106by the location registration information.

[Hardware Configuration of the IP-CNV]

A hardware configuration of the IP-CNV functioning as an access linktermination node is shown in FIG. 12. The IP-CNV 1202 comprises a CPU1204, a memory 1206 and external interface equipment 1212. The memory1206 includes self-location addresses 1208 and user ID information 1210.A location address set is uniquely provided for each access linktermination node (that is, for each IP-CNV), with storing its values inthe memory 1206 in advance as the self-location addresses 1208. Thememory 1206 also includes the user ID information 1210 for registeringuser identifiers corresponding to a self-visitor location subnetwork. Itcan also store telephone numbers and link identifiers like IMUI as otheruser ID information. The external interface equipment 1212 functions asan interface for connecting the IP-CNV 1202 to an IP network 1214 or aradio network 1216. For example, it functions as a router, DSU and TAthat are well known in the Internet technology. The CPU 1204 controlsthe memory 1206 and external interface equipment 1212. Specifically, aswill be described later in connection with another embodiment, the CPU1204 carries out access link management such as establishment or releaseof an access link taking the opportunity of user's access linkestablishment request or release request, receives a user locationregistration request (including user identifier) through the externalinterface equipment 1212, stores the user identifier into the user IDinformation 1210 in the memory 1206, provides the user with theself-location address 1208 through the external interface equipment1212, and transmits to the M-DNS the user location registrationinformation (including the self-location address and the identifier ofthe user) in response to the location registration request from theuser.

[Calling from a Mobile Station]

First, a procedure by which a terminal user of a mobile station acquiresa location address (LA) and learns his or her own IP address will bedescribed with reference to FIG. 3, when the user originates a callingthrough the Internet (as an IP host).

In FIG. 3, a terminal 302 like a mobile computer is connected to amobile station 304. An IP-CNV 306 is installed in a subscriber switchingsystem to be connected with the mobile station 304. The IP-CNV 306 isprovided with a location address LA as a visitor location subnetwork.

The terminal 302 has the user ID described above. The user (IP host) ofthe terminal 302 is about to establish an Internet connection with aparty user (IP client) 308 through the mobile station 304. The partyuser 308 may be a user either in the mobile communications system(mobile station) or in the outside of the mobile communications system(such as a public circuit network or public packet data network). Theuser 302 transmits a location registration request to the IP-CNV. Toachieve this, the user establishes an access link using an access linkmanagement means of the IP-CNV through a normal call setup procedure ofthe mobile station (step 301). Receiving the user location registrationrequest, the IP-CNV 306 notifies the terminal 302 of the self-locationaddress (LA) (1208 of FIG. 12) prestored as the visitor locationsubnetwork through the setup link (step 302). Incidentally, since theuser possesses his or her own user identifier, it is unnecessary for theIP-CNV to include the user identifier in the notification information.Thus, the IP-CNV can send a NULL signal (“0”s as in the presentembodiment, for example) as the user ID in the notification. Theterminal 302 completes its own IP address in the Internet using thenotified LA. More specifically, it places the notified LA and its ownuser identifier in the IP address. The IP-CNV 306 registers the user IDincluded in the location registration request into the memory (user IDinformation 1210 in FIG. 12) as the user location registrationinformation (step 303) so that the IP-CNV 306 can recognize the terminal302 as a terminal connected to this subnetwork. The terminal 302operates as an Internet terminal, and accesses the party user 308 usingits own IP address (including the LA and user ID) as its own callingaddress (step 304). The user 308 assembles a packet to be transmitted tothe terminal 302 by using as the terminating address (destinationaddress) the IP address that is notified as the calling address andincludes the LA of the terminal 302, so that the routing in the mobilecommunications network is carried out (step 305).

In this way, the terminal 302 transmits a packet using the IP addressincluding the LA and user ID as its own address, and can receive apacket from the party.

[Calling from Another User]

A calling procedure from the party user (IP host) 308 to the user (IPclient) 302 having the IP address including the LA in the mobilecommunications network will be described with reference to FIG. 4.

In FIG. 4, the user 308 is about to conduct a packet communication withthe user of the terminal 302 connected to the mobile station 304 in thenetwork, using the IP address including the LA and user ID. Let usassumed here that the access link of the mobile communications network(that is, the IP-CNV) to the user 302 has already been established(establishment of such an access link is not described here, because itwill be described later), and the relation between the IP addressincluding the LA at the access link establishment and the domain name(name) of the user 302 has already been registered in the database ofthe M-DNS 402, the domain-name server in the mobile communicationsnetwork (registration to the M-DNS is not described here, because itwill be described later).

First, the user 308 sends to the M-DNS 402 an inquiry including the nameof the user 302 (step 401). The M-DNS 402 searches the user informationdatabase (1106 of FIG. 11) using the name of the user 302, obtains theIP address of the user 302 including the corresponding LA and the like(step 402), and sends the IP address obtained by the search back to theuser 308 (step 403). The user 308 assembles a packet using the IPaddress obtained as the called address (destination address) andtransmits the packet. The mobile communications network carries outrouting in the network up to the subnetwork IP-CNV 306 using the LA inthe IP address (step 404). The IP-CNV 306 transmits the packet to theaccess link corresponding to the mobile station 304, using the user IDin the IP address (step 405). This enables the terminal user 302 toreceive the packet transmitted from the user 308. The user 302 assemblesa response packet by placing in its calling address section the IPaddress including its own LA, and sends the packet back to the user 308(steps 406 and 407).

In FIG. 4, the foregoing explanation is made on the assumption that theaccess link has been established with the terminal 302, and the relationbetween the IP address including the LA of the user 302 and the domainname (name) has been registered in the M-DNS 402. The establishment ofthe access link and the registration to the M-DNS 402 will now bedescribed in more detail.

[Establishment of the Access Link]

The establishment of the access link by the terminal 302 connected tothe mobile station can be implemented in the following two methods.

-   (1) Establishment of the access link taking the opportunity of power    up of the terminal.

The access link is automatically set up by the terminal 302 when themobile station 304 and terminal 302 is turned on, that is, when theterminal 302 becomes accessible from other terminals.

The establishment of the access link will now be described withreference to FIG. 5.

When the power of the mobile station 304 and terminal 302 is turned on,an access link is set up between the terminal 302 and the IP-CNV 306 inthe same manner as the call setup in the mobile communications network(step 501). The identifier of the user is sent to the IP-CNV as alocation registration request when establishing the access link. TheIP-CNV 306 sends the LA (visitor location subnetwork) assigned theretoback to the terminal (step 502). The terminal 302 completes its own IPaddress by recording the LA received. The IP-CNV 306 stores the user IDof the terminal 302 into the user ID information area (1210 of FIG. 12)in the memory as the user location registration information, and relatesthe IP address of the subnetwork in the Internet with the access link asthe mobile communications network (step 503). At the same time, itnotifies the M-DNS 402 of the IP address including the LA of theterminal 302 (step 504). The M-DNS 402 registers it in connection withthe domain name (name), using the user ID, for example (step 505).

-   (2) Establishment of the access link taking the opportunity of an    inquiry using the name.

As illustrated in connection with FIG. 4, when accessed by another user,an inquiry is sent to the M-DNS 402, first. The access to the terminal302, if it has not yet been established, can be carried out byestablishing the access to the terminal 302 taking the opportunity ofthe inquiry.

To achieve this, the M-DNS 402 is configured such that it has a flag forindicating whether an access link is established or not, and commandsIP-CNV 306 to establish the access link when the flag is in the OFFstate (that is, when the link is not set up). This will be described inmore detail with reference to FIG. 6.

In FIG. 6, the user 308 is about to transmit a packet to the user of theterminal 302 connected to the mobile station 304.

As in FIG. 4, the user 308 sends an inquiry including the domain name(name) to the M-DNS 402 (step 601) to have the name converted to the IPaddress (step 602). In this case, a complete IP address including the LAcannot be obtained, but only the user ID is obtained, because the flagindicating the access link establishment is in the OFF state. Thus, theM-DNS 402 tries to set up the access link (step 603). First, the M-DNS402, using the user ID sends an inquiry about the location address to anM-SCP 124 that manages the location and the like of the mobile station(step 604). The user ID must be made identical to the identificationnumber like the telephone number of the mobile station, which is used bythe mobile communications network for the location management. The M-SCP124 sends the LA indicating the location back to the M-DNS 402 (step605), and the M-DNS 402 makes a data entry of the LA in the database(step 606). Using the LA, the M-DNS 402 commands the related IP-CNV 306to set up an access link to the visitor mobile station 304 and terminal302 (step 607). Receiving the command, the IP-CNV 306 establishes theaccess link to the visiting user 302 (step 608). The user 302 learns thevisitor location subnetwork (LA) (step 609), and records the IP addressincluding his or her own LA in the terminal (step 610).

On the other hand, the M-DNS 402 sends back to the user 308 the IPaddress corresponding to the name (step 611). The user 308 assembles apacket using the IP address as the destination address, and transmitsthe packet (step 612). The IP-CNV 306, the routing destination, cantransfer the packet to the user 302 through the access link because theaccess link has been established by the time the packet is transferred.

In this way, the access link required can be set up taking theopportunity of the access to the M-DNS 402.

The update of the IP address including the LA that is registered in theM-DNS 402 can be made at the location update of the M-SCP.

[When Using a Telephone Number or the Like as a User Identifier of an IPAddress]

There is also a system that uses a telephone number in setting up anaccess link to a mobile station. Although the user ID can be madeidentical to the telephone number intentionally, the telephone number ofthe mobile station substantially differs from the user ID of the IPaddress which is independent of the mobile station to be connected.Accordingly, in the setup taking the opportunity of the access to theM-DNS 402, the M-DNS 402 can register not only the relationship betweenthe domain name and the IP address, but also the relationship betweenthe domain name and the telephone number.

When setting up the access link using a unique identifier(IMUI) affixedto a mobile station unrelated to the IP address, the domain name and theIMUI can also be registered in the M-DNS 402.

FIG. 7 is a diagram illustrating a process of registering in the M-DNS402 the telephone number or the IMUI of the mobile station 304 inconnection with the domain name (name) through a login procedure fromthe terminal 302 connected to the mobile station 304.

First, the terminal user 302 calls a special service that accepts thelogin, for example (step 701). Receiving the call, the IP-CNV 306 storesthe telephone number or IMUI (step 702), and sends an inquiry to theuser 302 about whether to carry out the login (step 703). The usercarries out the login using his or her own domain name and password(step 704). The IP-CNV 306 makes between it and M-DNS 402 the securitycheck of a domain name base using the password (step 705), and thenregisters the telephone number or IMUI stored in connection with thedomain name (step 706). The M-DNS 402 stores the telephone number orIMUI in the database in connection with the domain name (step 707).Thus, the M-DNS 402 can store the telephone number or IMUI incorrespondence with the name.

Using the telephone number or IMUI stored in the M-DNS 402 in connectionwith the name, an access link can be established taking the opportunityof the access to the M-DNS 402. This will be described in reference toFIG. 8.

In FIG. 8, the user 308 is about to transmit a packet to the user of theterminal 302 connected to the mobile station 304.

As in FIG. 6, the user 308 sends an inquiry including the domain name(name) to the M-DNS 402 (step 801) to have the name converted to thetelephone number or IMUI (step 802). In this case, because the flagindicating the access link establishment is in the OFF state, the M-DNS402 tries to set up the access link (step 803). First, the M-DNS 402,using the telephone number or IMUI, sends an inquiry about the locationaddress to an M-SCP 124 that manages the location and the like of themobile station (step 804). The M-SCP 124 sends the LA indicating thelocation back to the M-DNS 402 (step 805), and the M-DNS 402 makes anentry of the LA in the database to complete the IP address (step 806).The M-DNS 402 commands the IP-CNV 306 corresponding to the locationobtained to set up an access link to the visitor mobile station 304using the telephone number or IMUI (step 807). Receiving the command,the IP-CNV 306 establishes the access link to the visitor mobile station(step 808). The user 302 learns the visitor location subnetwork (LA)through the access link established (step 809), and sets up in theterminal the IP address including his or her own LA (step 810).

On the other hand, the M-DNS 402 sends back to the user 308 the IPaddress corresponding to the name (step 811). The user 308 assembles apacket using the IP address as the destination address, and transmitsthe packet (step 812). The IP-CNV 306, the routing destination, cantransfer the packet to the user 302 through the access link because theaccess link has been established by the time the packet is transferred.

[Hierarchically Structured LA]

In the IP address as shown in FIG. 2, the location address (LA) can takea hierarchical structure. Such an example will be described withreference to FIG. 9.

FIG. 9A illustrates a packet structure. A calling address 904 and acalled address 906 each include a location address (LA) with ahierarchical structure. FIG. 9B illustrates an example of thehierarchical structure. The prefix 908 in FIG. 9B indicates a type ofthe address structure. The LA 910 in FIG. 9B consists of a networkidentifier 912 and a node identifier 914. The network identifier 912indicates a unit obtained by subdividing the mobile communicationsnetwork to some areas. The node identifier 914 identifies the IP-CNV,and constitutes an interface between the packet routing and the accesslink to a mobile station in the mobile communications network. The useridentifier (user ID) 916 is a number unique to the user, which is fixedregardless of the roaming of the user in the mobile communicationsnetwork.

FIGS. 10A and 10B illustrate an example of routing when using, as theuser identification information including the LA in the network, thetotal of 12 bits, consisting of a 4-bit network identifier 912, a 4-bitnode identifier 914 and a 4-bit user identifier (user ID) 916.

In FIGS. 10A and 10B, a user X of a calling user terminal 812 connectedto a network NW3 810 inside or outside the mobile communications networkis about to transmit a packet 800 to a user F of a called user terminalconnected to a mobile station 850 in a subscriber node D in NW1 820 inthe mobile communications network (the network identifier, nodeidentifier and user identifier of the called user terminal are “1010”,“0101” and “0001”, respectively).

The networks 820 and 830, and subscriber nodes 824, 826, 828, 834 and836 are each provided with a network identifier and a node identifier.The network NW1 820 is provided with a network identifier “1010”, andthe network NW2 830 is provided with a network identifier “0101”. Thesubscriber node C 824 is provided with a node identifier “1100”, thesubscriber node D is provided with a node identifier “0101”, and thesubscriber node E is provided with a node identifier “0011”. Thesenetworks include routing nodes 814, 822 and 832 for routing packetstransmitted thereto.

The packet 800 from the user terminal 812 is assigned as the callingaddress a network identifier, node identifier and user identifier of“1010”, “0101” and “0001”, and is transmitted. A routing node 0 814 inthe NW3 810, to which the user terminal 812 is connected, carries outrouting of the packet 800 using the network identifier (1010), andtransmits it to the network NW1 820. In the network NW1 820, the routingnode A 822 routs the packet to the subscriber node D 826 using the nodeidentifier (0101).

The subscriber node D 826 sets up an access link using the useridentifier (0001), and transmits the packet 800 to the mobile station850. The mobile station 850 is connected to two terminals, one of whichis the terminal 852 whose user identifier is “0001”. Thus, the terminal852 receives the packet 800.

In this way, using the network identifier and node identifierconstituting the location address LA enables a direct routing to an areavisited by a mobile station (an area 860 in which the user F is visitingin the foregoing example).

Although the foregoing routing is made in accordance with the locationaddress with the hierarchical structure, direct routing of the packet800 can also be made to the subscriber node D using the entire locationaddress (“10100101”) in the routing node 0.

Thus incorporating the location address in the address in the packetenables the direct routing of the packet using the address.

While the present invention has been described in detail with respect topreferred embodiments and methods, it will be understood that numerousmodifications, changes, variations and equivalents will be made by thoseskilled in the art without departing from the spirit and scope of theinvention.

In addition, specified elements, techniques and embodiments can also beapplied to the teachings of the present invention by implementingvarious changes without departing from the substantial idea of thepresent invention. Accordingly, it is intended that the invention hereinbe limited only by the scope of the appended claims.

INDUSTRIAL APPLICABILITY

As described above, the packet transmission method, packet transmissionsystem and packet data transmission medium on the mobile communicationsnetwork system in accordance with the present invention is suitablyapplicable to the packet transmission according to the IP.

1. A processing method in a mobile communications network system forrouting a packet using an IP address between a user in a mobilecommunications network system and a user inside or outside the mobilecommunications network system, the processing method comprising thesteps of: generating, at a domain-name server, an IP address of the userin the mobile communications network system including a location addressof the user and a user identifier which identifies the user, byacquiring the location address from an apparatus managing a locationaddress of the user; and storing the generated IP address in connectionwith a domain name of the user in the mobile communications networksystem, in a database in the domain-name server, the processing methodfurther comprising the steps of: referring to a memory managing accesslink establishment status of a user in the domain-name server, when aninquiry regarding the user is sent to the domain-name server; commandingan access link termination node in whose area the user is visiting, toestablish an access link, if an access link is not established for theuser; establishing, at the access link termination node, an access linkbetween the access link termination node and the user; and providing, atthe access link termination node, the user with the location address,when the access link is established.
 2. The processing method as claimedin claim 1, further comprising the step of setting a flag indicatingaccess link establishment in the memory managing access linkestablishment status, when the access link is established and the IPaddress is newly registered.